Personal experience ofc, but a lot of people argue in bad faith. Knowingly (or unknowingly) invoke logical fallacies, whataboutisms and straw man arguments. With how ideologically volatile the internet has turned in recent years, you can't really have a reasonable argument any more without it becoming just a name calling session.
Yesterday I noticed just how much reddit had jaded me. Had a bbq with some friends and a guy I knew was very much in the right, q anon stuff and all, asked me about my position on polarizing topics. I'm anarcho syndicalist. Expected it to get heated. Dude just genuinely asked questions and that was it. No trying to prod holes into the ideology or show the superiority of his ideology. It was kinda eye opening and showed me I just spent too much time in toxic areas of the internet. Though he seemed to have a bone to pick with the stereotypical city dweller lib. Had I had those positions he probably would've unloaded with quotes from the usual suspect talking heads.